Portable hair drier with heat storage and self-generating circulating means



July 9, 1968 C. CHEDISTER PORTABLE HAIR DRIER WITH HEAT STORAGE AND SELF-GENERATING CIRCULATING MEANS,

4 Sheets-Sheet 1 Filed May 10, 1966 ATTORNEYS July 9, 1968 c. CHEDISTER PORTABLE HAIR DRIER WITH HEAT STORAGE AND SELF'GENERATING CIRCULATING MEANS 4 Sheets-Sheet 2 Filed May 10, 1966 J y 9. CC'HEDST ER 3.391.470

AND SELF-GENERATING roaming: HAIR DRIER WITH am'r s'rpnmn CIRCULATING MEANS '4 Sheets-She. 5

Find m 10. 1966' ail/v 1/ u h-9 S ay: H 1 "LU y 9. 1968 c. CHEDISTER 3,391,470

PORTABLE HAIR DRIER WITH HEAT STORAGE AND SELF-GENERATING CIRCULATING MEANS 4 Sheets-Sheet 4 Filed May 10, 1966 INVENTOR C'wa 1N9 di/e'o/s r52 l I M 9 PM ATTORNEYS United States Patent 01566 3,391,470 Patented July 9, 1968 Conkling Chedister, Madison, N.J., assignor of one-half 5 to Marcel Suter, Cincinnati, Ohio Filed May 10, 1966, Ser. No. 549,028 16 Claims. (Cl. 34-99) ABSTRACT OF THE DISCLGSURE This invention relates to a portable hair drier which permits the user to move about without restriction during the drying operation. Within the drier an electric heating element is energized by an electrical source apart from the drier. At the same time, heat is stored in the drier by heat storage means thermally coupled to the heating element. Thereafter, the heating element is disconnectable from the electrical source so that the user can move about without restriction during the drying operation. Self-generating circulating means provided in the drier cause air to circulate therewithin in such manner that the air is heated prior to drying hair.

For drying hair present portable driers commonly circulate heated air within a hood worn by the user. Either heating elements within the hood or a separate electric air heating and blowing unit connected to the hood by a hose is used to heat the air. To properly dry the hair the electrically operated heater and blower as well as the heating elements, must be connected to an electric wall socket by means of a power cord throughout the drying operation. This greatly restricts the movements of the user inasmuch as the user must remain in the immediate vicinity of the wall socket. In addition, the separate electric blower and heating unit is cumbersome and a nuisance to maintain in position during the drying operation.

Another problem with present portable hair driers is that the heated air circulated within the hood is not maintained at a temperature throughout the drying operation that efficiently dries hair without making the user uncomfortable. When the hair contains the greatest amount of moisture, the heated air can be at the maximum temperature because such air can pick up sufficient moisture to make it feel relatively cool as it passes over the scalp of the user. This occurs at the outset of the drying operation. If the temperature of the heated air remains constant, however, as the moisture content in the hair decreases during the drying operation, the heated air will not pick up suflicient moisture to make it feel relatively cool to the scalp. Rather, such air will raise the temperature of the scalp to an uncomfortable level. Although some driers have manually operated controls for lowering the temperature of the heated air, the user commonly does not make the adjustment, or the user does not make the proper adjustment. Consequently, as the hair drys either the temperature of the heated air becomes too high making the user uncomfortable, or the temperature of the air is too low for drying the hair at an efiicient rate.

Furthermore, in present hair driers containing heating elements, the elements are commonly placed too close to the hair and scalp of the user. As a result, great care must be exercised by the user to prevent burning of the hair and scalp. Moreover, present hair driers do not provide means for directly inspecting the condition of the hair as it is being dried. Also, some so-called portable hair driers are too heavy and do not have their weight properly distributed on the drier so that they are cumbersome and tiresome to wear.

It is, therefore, one object of this invention to provide a new and improved hair drier which will overcome the foregoing problems as well as permit the user to move about without restriction.

It is another object of this invention to provide an electrically operated hair drier that will permit the user to move about without restriction.

It is still another object of this invention to provide a cordless electrically operated portable hair drier which provides heat for drying hair without the need for electrical connection while the hair is being dried.

It is a further object of this invention to provide a portable hair drier that employs heated air wherein the temperature of said air is automatically maintained at a comfortable level while efliciently drying the hair.

It is another object of this invention to provide means for maintaining the hood of the drier in the proximity of the hair to be dried without any chance of burning either the scalp or the hair of the user.

It is still another object of this invention to provide a drier which will permit inspection of the condition of the hair without removing the drier.

It is a further object of this invention to provide an electrically operated hair drier of light weight construction with the weight thereof distributed on the drier so that it can easily be worn by the user throughout the drying operation.

In accordance with the present invention there is provided a portable hair drier havin a hood shaped to conveniently rest upon the users head. The hood contains a heating element of relatively large area so shaped that when the hood encloses the scalp the element is distributed about the hair to be dried. Moreover, the heating element is positioned within the hood so that air circulated therewithin is heated prior to passing through and over said hair. Thermally coupled to the heating element are means for storing and confining the heat that has been developed by the element to Within the hood so that the element does not have to be connected to an electrical source throughout the entire drying operation; and wherein said means preferably automatically reduces the temperature to which the air is heated to efficiently dry hair While maintaining the temperature of the air at a level that will be comfortable to the user throughout said drying operation. For heating the element there are circuit means within the hood adapted to be connected to a fixed electrical source, as to a wall socket or the like, to energize the element at the outset of the drying operation and to store heat within the hood, but which are thereafer disconnected from the fixed electrical source, to thereby allow the user to move about without restriction. For circulating air within the hood and for allowing the user to move about without restriction, the drier also includes a self-generating electrically operated circulating means secured thereto that preferably includes a blowing unit energized by a battery.

In the preferred embodiment of the present invention the portable hair drier includes a pair of spaced sheaths which form a hood that is shaped to conveniently rest upon the users head, and which store and confine heat within the hood. An adjustable band is provided which encircles the head at the forehead and the base of the head, and is connected to the sheaths so that the entire drier is supported on the users head and so that air will not escape through the bottom of the hood. At the top of the hood is an opening which extends through the sheaths for the escape of air that has been heated and has also passed through the moist hair so that it is heated and moisture laden and is therefore lighter and tends to rise. The opening is also large enough to enable the user to check the dryness of the hair at any time by simply inserting a finger through the opening and feeling the hair. To maintain the hood spaced from the users scalp there is provided a collapsible band Within the hood which extends across the top portion thereof and which has a free end that extends through the hood and is attachable to the outside of the hood. When the drier is to be used for hair that does not contain anything that will naturally space the hood from the hair, such as curlers, the band is simply pulled taut and its free end is attached to the hood whereupon the hood is spaced from the users scalp and the band supports the hood on the users head. If the hair does contain curlers that will naturally space the hood from the scalp of the user, the band is maintained in its collapsed position. To permit the user to determine the dryness of the hair, the band is also provided with an opening in alignment with the opening in the top of the hood.

The inner sheath of the drier is air pervious and contains a resistance heating element of relatively large area and so shaped that when the hood encloses the scalp, the element is distributed about the hair to be dried. Desirably, the inner sheath is of a heat storing material in which is embedded the heating element to thereby form a heat storing means for the element, and wherein said sheath has a plurality of apertures therein positioned adjacent said heating element. Furthermore, the outer sheath is made of air impervious heat storing material to prevent outward dissipation of heat.

For heating the resistance heating element the hood contains circuit means connected to the element that are adapted to be connected to a wall socket to heat the element prior to placing the hood upon the head. After the element has been heated the circuit means are disconnected from the wall socket and the hood is placed upon the head of the hair to be dried. To provide a temperature control for the element the drier desirably includes a thermostat connected to the heating element which can be regulated by the user to vary the temperature to which the element can be heated.

In this embodiment of the invention, the blowing unit is attached to the outside of the hood to blow air into the space between the inner and outer sheaths. The air then passes through the inner air pervious sheath, and in so doing is heated by the heating element. The heated air thereafter passes through the hair to be dried and is eX- hausted through the opening in the top of the drier. Preferably, the blowing unit is energized from a rechargeable battery circuit positioned to balance the weight of the blowing unit when the hood is upon the user.

In one embodiment of the invention the heating element is energized and the battery is recharged by providing a projection on the drier that contains contacts which are connected to the circuit means for the heating element and to the recharging circuit, and includes a separate independent unit into which the projection is insertable. Housed within the unit is an energizing circuit adapted to be connected to household electrical source and which includes contacts adapted to be connected to the contacts of the circuit means 011 the drier projection to energize the heating element for a predetermined time to obtain the desired temperature. After the element has been connected to the energizing circuit for the specified time, the energizing circuit will automatically stop heating the element and the drier is ready for use. Also housing within the unit is a recharging circuit that is adapted to be connected to the same household electrical source, and likewise includes contacts which are adapted to be connected to the contacts of the recharging battery circuit on the drier projection. Actuation of the energizing and recharging circuits within the unit is achieved by connecting said circuits to a fixed electrical source, such as a wall socket, and by inserting the projection on the drier into the unit to thereby connect the contacts thereon with the contacts of the energizing and recharging circuits.

Additional objects and advantages of the invention will be set forth in part hereinafter and in part will be obvious herefrom, or may be learned with practice with the invention, the same being realized and attained by means a! of the steps, combinations and improvements pointed out in the appended claims.

The accompanying drawings referred to herein and constituting a part hereof illustrate one embodiment of the invention, and together with the description serve to explain the principles thereof.

FIGURE 1 is a sectional view of the drier of the present invention and illustrates the drier in use along with having certain parts broken away to show the interior construction of the drier;

FIGURE 2 is a sectional view schematically showing the drier of my invention in use when the hair of the user has been set in curlers;

FIGURE 3 is a schematic wiring diagram or the drier shown in FIGURES 1 and 2, coupled with a schematic wiring diagram of a unit for heating the resistance heating element as well as for recharging the self-energizing unit;

FIGURE 4 is a sectional view of the hood contained within a casing having a compartment containing the recharging and energizing unit, and having the blowing unit in position for heating the resistance heating element and recharging the self-energizing unit;

FIGURE 5 is a sectional View of the blowing unit and a portion of the recharging and energizing unit, particularly illustrating the contacts therebetween;

FIGURE 6 is a plan view of the compartment in the carrying case showing the door in its closed position;

FIGURE 7 is a plan view of a portion of the compartment in the carrying case showing the door in its open position;

FIGURE 8 is a sectional view of a portion of FIGURE 6 taken along the lines 8 S thereof;

FIGURE 9 is a sectional view of FIGURE 8 taken along the lines 9-9 thereof;

FIGURE 10 is a sectional view of FIGURE 5 taken along the lines 1tl1fi thereof;

FIGURE 11 is a perspective view of the door of the compartment in the carrying case.

Referring now to the illustrative embodiment of the present invention, as shown in the drawings, the drier, generally designated 10, includes a hood 12, that conveniently fits upon the head and over the hair of the user. The hood 12 has a semicircular cross section and includes a self-supporting outer sheath 14 and a selfsupporting inner sheath In which are coextensive and slightly spaced from each other to define an air passage 18 therebetween. Extending through the top of the hood 1?; is a relatively large opening 20 for exhausting moisture laden air that has been heated and has also passed through or over the moist hair being dried. The opening 20 is relatively large to also permit access into the hood 12 to check the dryness of the hair at anytime during the drying operation.

Both the sheaths 14 and 16 are made of a lightweight heat storable material, such as fiberglass, that will withstand a temperature of 350 F. for extended periods. The outer sheath 14 forms an imperforate fiberglass shell to confine the heat developed within the hood 12. The inner sheath 16 includes two superimposed fiber glass layers 22 and Z4 bonded together. Between the layers 22 and 24 of the inner sheath 16 and covering a large part thereof, preferably at least one-third of this area, is a resistance heating element 26, wherein the surrounding fiberglass material stores the heat developed by the element 26 while it is energized for use in drying the hair. For the passage of air, the inner sheath 16 includes a plurality of apertures 28 spaced from one another in a predetermined pattern so that they are evenly distributed over the entire area of the inner sheath 16 adjacent the resistance heating element 26. Preferably sufiicient apertures 28 are provided to give about 20 to 40% porosity. Moreover, the element 26 and the sheath will automatically heat the air passing through the apertures 28 to a gradually decreasing temperature to efficiently dry the hair throughout the drying operation without making the user uncomfortable. In so doing, the sheath 16 and element 26 provide maximum heat at the outset of the drying operation when the moisture content of the hair is at a maximum. Accordingly, the air passing through the apertures 28 is heated to the maximum temperature and picks up the maximum amount of moisture from the hair but still feels relatively cool to the scalp of the user because of the high moisture content of the heated air. Thereafter the sheath 16 and element 26 gradually give up heat at a controlled rate that is correlated to the decrease in the moisture content of the hair so that the air passing through the hair will still efficiently pick up moisture and continue to feel relatively cool to the scalp of the user as it passes theneover.

As shown in FIGURES 1 and 3, the resistance heating element 26 is preferably divided into a plurality of elements each of which is formed from a thin sheet, from 0.003 inch to 0.008 inch thick resistance alloy, such as Nichrome, or other poorly conductive material which will be durable at operating temperatures, usually from 300 to 350 F. The elements are usually formed as a sheet, the opposite edges of which are alternately slotted, as at 30, to provide a long resistance path of generally uniform cross section so that it will be evenly heated by the passage of current through it. These elements are preferably similar in thickness and are connected in series so that their temperatures will be about the same. Two such elements 32 are placed on opposite sides in the middle portion of the hood (only one shown). A third element 34 is placed about the front portion of the hood 12 and is opposed by a fourth element 36 placed about the rear portion of the hood 12 (see FIGURE 3).

Because the hood 12 is of light weight it may be supported directly by the users head. However, to permit circulation of air within the hood 12 and to insure against burning the hair or scalp, the hood 12 is not placed in direct contact with the hair but is maintained in close proximity thereof by adjustable means within the hood 12 as will now be described. As shown in FIGURE 1 there is provided within the hood 12 a collapsible air pervious band 38 that extends across its top portion. The fixed end 40 of the band 38 is attached to the inner surface 42 of the inner sheath 16 as by a screw 44. The free end 46 of the band 38 extends through a slot 48 in the sheaths 14 and 16, and has a slot therein (not shown) which may be placed about the knob 50 attached to the top outer surface 52 of the outer sheath 14 adjacent the top portion of the hood 12. A hollow cylindrical tube 54 forming a wearing member is inserted in the slot 48 and the band 38 extends through such tube 54. The ends 56 of the tube 54 are turned out and engage the adjacent surfaces of the sheaths 14 and 16 to secure the wearing tube 54 to the hood 12.

Extending through the band 38 is an opening 57 which is in alignment with the opening 20 through the top of the hood 12 to allow the escape of moisture laden air and to permit inspection of the condition of the hair at all times. The band 38 is preferably formed of porous heat resistant textile fabric in which the openings between adjacent warp and filling yarns are approximately the same as the diameter of the yarns, thereby giving from 20 to 40% porosity. The band 38 is formed of a material that will withstand heat generated by temperatures of 350 F. for extended periods, and I have found that flexible glass textile fabrics are ideally suited for this purpose as they are fire-proof and lightweight.

If the hair of the user is going to be dried without any curlers or the like, then the band 38 is pulled taut as shown in FIGURE 1 and its free end 46 is attached to the knob 50. Accordingly, the band 38 will rest directly on the users head while the somewhat larger hood 12 is maintained a short distance from the hair. If, on the other hand, the hair of the user contains curlers or the like as shown in FIGURE 2, then the hood 12 will naturally be spaced from the scalp of the user when it is placed upon the users head. In such event, the band 38 need not be pulled taut but may remain collapsed as shown in FIGURE 2.

To maintain the hood 12 on the head of the user and to prohibit the flow of cold air into the interior of the hood 12, the bottom of the hood 12 is provided with an adjustable head ring 58, and an annular band 60 of heat resistance flexible impervious material, such as a fiber glass fabric. The annular band 60 is connected at the outer periphery 64 to the bottom of the inner sheath 16, as by sewing or heat sealing, and the inner periphery 66 is connected to the head ring 58.

The head ring 58 includes a plurality of spaced vertical loops 68 secured to the outside thereof, and a tie string 70 that extends through the loops 68 and which may be tied at the forehead. In use, the ring 58 rests in front on the forehead and in the rear at the back of the head adjacent the hair line as shown in FIGURES 1 and 2.

To close the air passage 18 between the sheaths 14 and 16 at the bottom of the hood 12, the inner layer 22 of the inner sheath 16 is of greater length than the outer layer 24 so that the free end 72 can extend across the bottom of the air passage 18 and be secured to the outer surface 52 of the outer sheath 14. At the front of the hood 16, the free end 72 of the inner layer 22 is provided with a slot (not shown) so that the lower portion of a housing 74 can be attached to both sheaths 14 and 16, as shown in FIGURES 1 and 2.

A blowing unit 76 forces air into the hood 12 through an opening 78 in the outer sheath 14 adjacent the base of the hood 12. The unit 76 includes a hollow cylindrical housing 80 that communicates with the opening 78 and which has an annular flange that is secured to the outer sheath 14 about the opening 78. About the periphery of the housing 80 there are three annular spaced contact rings 84, 86 and 88, and upon the bottom of the housing 80 is a switch plate 90, all used in the recharging and heating unit as will be described hereinafter. A fan 92 is located within the housing 80 adjacent the opening 78 and is driven by a motor 94 secured to the housing 82 by four equally spaced radially extending struts 96 welded to the motor 94 and the housing 82. Air is drawn by the fan 92 from the surrounding atmosphere through openings 98 in the base of the housing 80 and an air fiiter 100 secured between the fan 92 and the openings 98.

The motor 94 is driven by a self-contained energizing unit 102 that is preferably attached to the front portion of the hood 12 within the housing 74 positioned to balance the weight of the blower unit 76 when the hood 12 is upon the head of the user. Access into the housing 74 can be obtained by removing the screw 104 used in securing it to the hood 12. The energizing unit 102 includes a battery 106 connectable to drive the motor 94 via a pair of conductors 108 and 110 which are positioned in passage 18. A three position switch 112 extends from the housing 74 and includes a pair of stationary contacts 114 and 116 and a movable contact 118. The contact 114 is connected to the conductor 110 and the movable contact 118 is connected to the battery 106. As shown, switch 112 is in the opened position. The motor 94 is energized by the circuit completed through movable contact 118, stationary contact 114, and conductors 108 and 110.

The battery 106 is preferably recharged from an ordinary household source of alternating current. For this purpose the unit 102 includes a pair of conductors 120 and 122 positioned within the passage 18 and connected at one end to the annular rings 86 and 88 on the housing 80, respectively, and at the other end to a diode rectifying circuit 124 which converts the household AC current to DC current. The rectifying circuit 124 is connectable to the battery 106 via contact 116 and movable contact 118. Thus, the battery 104 is charged by moving contact 118 into engagement with stationary contact 116 and by connecting the annular rings 86 and 88 with household current.

The heating element 26 is connected between the contact rings 84 and 86 in series with a thermostat 126 by conductors 128 and 130. When rings 84 and 86 are connected to the household current, heat will be provided by current flow through the resistance heating element.

As previously described, the hair drier of the invention automatically maintains the temperature of the heated air at a comfortable level while efiiciently drying the hair. In one embodiment of the invention this is accomplished by having a hood 12 with an opening 20 of two inches in diameter and an inner sheath 16 having a porosity of about 20%. A thin Nichrome heating element 26 that covers about Vs the area of the sheath 16 is also provided and is heated to a temperature of about 350 F. After placing the hood 12 upon the user a battery operated fan 96 feeds about six cubic feet per minute into the space 18 between the sheaths 14 and 16. The air then passes through the apertures 28 and in so doing is heated by the element 26 and the surrounding fiber glass sheath 16. At the outset the air is heated to the maximum temperature and in passing over or through the wet hair it picks up sufiicient moisture to make the moisture containing air feel relatively cool as it passes over the scalp of the user. As the drying operation continues the amount of heat stored in the fiberglass sheath 16 and element 26 gradually decreases at a controlled rate relative to the decrease of the moisture content of the hair. Accordingly, at all times the heated air etficiently picks up moisture from the hair but continues to feel relatively cool to the scalp. Throughout the drying operation the moisture laden air escapes through the opening 20 at the top of the hood 12. Furthermore, the user is able to move about without restriction and is able to check the condition of the hair being dried by simply inserting a hand through the opening 20 and feeling the hair. After the user determines that the hair is dried the hood 12 is removed.

The manner in which the recharging circuit and the heating element are connected to the household source will now be more fully explained.

In the preferred embodiment the recharging and heating control unit 134 is housed in a compartment 136 within the bases portion of a carrying case 138 for the drier as illustrated in FIGURE 4. In the top plate 140 of compartment 136 there is an entrance 142 through which the drier cylindrical housing 80 can pass into a well 144 that extends upwardly from the base plate 146 as shown in FIGURE 5. When the housing 80 is positioned within well 144, contact rings 84, 86 and 90 are aligned with three arcuate slots 148 that extend through the wall of the well 144.

To prevent inadvertent entrance into the compartment 136 there is provided a door 150 directly underneath the entrance 142. The door 150 is opened and closed by rotation about a bolt-like member 152 that extends through a hollow post 154 depending from one corner of the door 150. At its upper end the bolt 152, in turn, extends through a bore 156 in the top plate 140 adjacent the entrance 142 and is threaded at its lower end into the base plate 146 as shown in FIGURE 8.

To facilitate the movement of the door 150 in a controlled manner, there is a knob 158 that is secured to the corner of the door 150 opposite the post 154 that extends through and is slidable in an are shaped slot 160 in the top plate 140. The length of the slot 160 corresponds to the distance the door 150 must be moved to completely open the entrance 142. The end 162 of the slot 160 is accordingly positioned a distance from the entrance 142 which corresponds to the distance needed to fully open the entrance 142 so that when the knob 158 abuts said end 162 the door 150 will be in its closed position (see FIG. 6). A helical spring 166 wrapped about the post 154 0 with one free end 168 abutting one side of the door and with the other free end 170 engaging a knob 172 that depends from the plate 140, constantly urges the door 150 to its closed position. To open the door 150 the user simply moves the knob 158 from one end 162 of the slot 160 to the other end 164 against the biasing action of the spring 166 and then slidably inserts the cylindrical housing 80 through the entrance 142 and into the well 144. The well 144 thereafter supports the housing 81) and the housing 81), in turn maintains the door 158 in its open position.

In addition, depending from the door 150 adjacent the post 154 is a channel 174 that has three spaced contact fingers 176, 178 and 188 extending therefrom. The channel 174 and fingers 176, 178 and 188 are positioned such that as the door 158 is opened, the fingers 176, 178 and 180 will move into the slots 148 in the well 144 ready for contact with the annular rings 84, 86 and 88, and as the door 150 is closed the fingers 176, 178 and 188 will move out of the slots 148. Thus, the possibility of inadvertent contact with rings 84, 86 and 88 is minimized.

As shown in FIGURE 3, the two lower fingers 178 and 180 are connected to conductors 132 and 184 which are, in turn, connected to a plug 186. With the plug 186 connected to a household source and with the hood 12 inserted in the well 144 all the user need do for recharging the battery is to complete the charging circuit via contacts 116 and 118. Current then flows from the source, through fingers 178 and 180, annular rings 86 and 88, rectifying circuit 124 and battery 106. When the battery 106 is recharged, the switch 112 may be moved to its open position.

The energizing circuit for the element 26 includes contact switch 188 secured to the lower base plate 146 of compartment 136 within the well 144 that is completed via switch plate 90. The contact switch 188 is connected between conductors 182 and 184 in series with a coil 190 of a relay 192. Thus, when the housing 80 is inserted into the well 144 the switch plate 90 completes the circuit energizing the coil 190 to close the normally open relay contacts 194. The contacts 194 are connected in series with finger 176 and, when closed, complete the circuit for heating the element 26. Current then flows from one side of the line through finger 178, ring 86, conductor 128 within the hood 12, element 26, conductor 130, thermostat 126, and then through ring 84, finger 176 and contacts 194 to the other side of the line.

When the housing 80 of the hood 12 is placed in the well 144, the control circuit within compartment 136 energizes the element 26 for a controlled period of time sufficient to store the proper amount of heat in the surrounding fiberglass layers 22 and 24 of sheath 16 as will be required for drying the hair. During the heating interval the thermostat 126 controls the temperature of the element 26 in accordance with the selected setting of the knob 132.

The element 26 within the hood 12 is energized from the power lines 182 and 184 when an electromechanical relay 192 in compartment 136 is energized, that is, providing housing 80 is in well 144 and contact rings 84, 86 and 88 are coupled to contact fingers 176, 178 and 180, respectively. Power line 184 is connected to one end of heating element 26 via normally open contacts 194 of relay 192, contact finger 176, contact ring 84, thermostat 126 and conductor 130, while the other end of the element 26 is connected to the other power line 182 via conductor 128, contact ring 86 and contact finger 178. Thus, the heating element is energized while relay 192 is energized to close its associated contacts 194.

The time interval for energization of relay 192 is controlled -by means of a time delay tube 196 including a set of normally closed bimetallic contacts 198 thermally coupled to a heater 200. Heater 200 is connected between power lines 182 and 184 in series with contacts 194 of the relay 192 and is therefore energized whenever heating element 26 within the hood 12 is energized. Contacts 198 of the time delay tube 196 form part of a series circuit including a contact switch 202 and a coil 190 of relay 192, this series circuit being connected between power lines 182 and 184. Contact switch 202 includes the pair of spaced apart contacts 188 mounted at the bottom of well 144 and positioned to engage the contacts of switch plate 90 whenever housing 80 is positioned in the well as shown in FIGURE 5.

Accordingly, when contact switch 202 is closed by insertion of housing 80 in the well, relay coil 190 is energized via the contact switch and the normally closed contacts 198 in the time delay tube 196. When contacts 194 of relay 192 close, the heating element 26 in the hood 12 and the heater of time delay tube 200' are both energized. After a predetermined period of time as determined by the time constant of time delay tube 196, contacts 198 open to de-energize relay 192 to thereby open contacts 194 and terminate energization of the heating elements. A lamp bulb 204 is connected across the coil 190 of the relay 192 and hence, is energized when the relay 192 is energized. As shown in FIGURE 4, the bulb 204 is positioned where it can be seen by the user, and provides a visible indication of the heating cycle termination.

In a typical hair drying operation, the user will first open door 150 and insert drier housing 80 into well 144 to automatically close contact switch 202 and couple contact rings 84, 86 and 88 to their associated finger contacts 176, 178 and 180. This automatically initiates the heating cycle as indicated by lamp bulb 204. The switch 112 on the hood is placed in the battery charging position to recharge battery 106, and thermostat 126 is set to the desired hair drying temperature. During the heating cycle heat is stored in the fiberglass layers 22 and 24 surrounding the element 26. When lamp bulb 204 becomes extinguished, this indicates that the heating cycle is completed and that the hood 12 can then be removed and adjusted upon the head of the user. Thereafter, the switch 112 is moved to the position to energize the fan 96 from battery 106. The fan 96 feeds air into the space 18 and then through the fiberglass layers 22 and 24 in which the heat has been stored via apertures 28. In this manner the air is heated and therefore the hair is dried as this heated air passes therethrough toward opening 20 in the top of the drier 10. As the moisture content of hair decreases the stored heat correspondingly decreases so that the heated air will always be at a comfortable level while efliciently drying the hair.

The invention in its broader aspects is not limited to the specific embodiments herein shown and described but departures may be made therefrom within the scope of the accompanying claims, without departing from the principles of the invention and without sacrificing its chief advantages.

What is claimed is: v

1. A portable hair drier that allows the user to move about without restriction, comprising a pair of sheaths that encircle the head of the hair to be dried, the outer one of said sheaths being air impervious to confine heat within said drier, the inner one of said sheaths being air pervious and positioned in proximity of the hair to be dried, a resistance heating element contained by said inner sheath for heating air that passes therethrough before said air passes through and over the hair to be dried, circuit means within said hood connected to said element and adapted to be connected to an electrical source apart from said drier to energize said element and for storing heat within said inner sheath at the outset of the drying operation, said circuit means being thereafter disconnectable from said electrical source so that the user can move about without restriction, an electrically operated blowing means mounted on said drier for causing air to pass through said air pervious inner sheath, and battery means mounted on said drier for energizing said blowing means.

2. The drier set forth in claim 1 wherein said sheaths are spaced apart from one another and said blowing means is secured to said outer sheath so that air is fed into the space between said sheaths and then through said inner air pervious sheaths.

3. The drier set forth in claim 1 wherein said sheaths provide an opening therethrough at the top of the drier for exhausting moisturecontaining air that has been heated and has also passed through or over the hair being dried, and wherein said opening is large enough to permit the user to directly feel the hair while the drier is upon the head of the user.

4. The drier set forth in claim 3 wherein said inner air pervious sheath has a plurality of relatively small apertures therethrough evenly distributed over the entire inner sheath, and wherein said resistance heating element is embedded within said inner sheath adjacent said apertures and is of a thin flexible resistance material whose area is a relatively large proportion of the area covered by said inner sheath.

5. The drier set forth in claim 1 wherein said drier is provided with adjustable means for maintaining said inner sheath out of contact with the head of the user, said adjustable means including a collapsible band within the drier that extends thereacross and which rests directly upon the head of the user, said band having one end attached to said inner sheath and having the other end thereof extending through said sheaths, and means on said drier to which the free end of said collapsible band can be attached to thereby make the band within the drier taut and space said inner sheath from the head of the user.

6. The drier set forth in claim 5 wherein said collapsible band is air pervious and has an opening therethrough that is in alignment with said opening extending through the top of said sheaths.

7. The drier set forth in claim 1 wherein said battery means is attached to the front portion of said outer sheath and said blowing means is connected to the base of said outer sheath to thereby balance the weight of said means upon the head of the user.

8. The hair drier set forth in claim 1 wherein said battery means includes a rechargeable battery, and further comprises circuit means connected to said battery adapted to be temporarily connected to an electrical source apart from said drier for recharging said battery.

9. The hair drier set forth in claim 1 wherein there is provided means controllable by the user for regulating the temperature of said resistance heater element.

10. The hair drier set forth in claim 9 wherein said means is a thermostat mounted on drier.

11. A portable hair drier that allows the user to move about without restriction, comprising a pair of spaced sheaths that encircle the head of the hair to be dried, and having an opening therethrough at the top of said drier of sufficient size to allow the user to feel the hair while the drier is upon the head of the user, the outer one of said sheaths being of an air impervious material to confine heat within said drier, the inner one of said sheaths being in proximity of the hair to be dried and being air pervious, a resistance heating element contained within said inner sheath wherein said inner sheath about said element stores heat developed by said element for automatically heating air that passes through said inner sheath to a temperature that efliciently drys the hair and maintains said temperature at a comfortable level throughout the drying operation, circuit means within said hood connected to said element and adapted to be connected to an electrical source apart from said drier to energize said element and for storing heat within said inner sheath at the outset of the drying operation, said circuit means being thereafter disconnectable from said electrical source so that the user can move about without restriction, an electrically operated blowing unit mounted on said drier for causing air to pass through said inner air pervious sheath, rechargeable battery means mounted on said drier including circuit means connected to said blowing unit, a recharging circuit for said battery adapted to be connected to an electrical source apart from said drier for recharging said battery, said recharging circuit being disconnectable from said electrical source so that the user can move about without restriction, and switch means for selectively connecting said battery to said circuit means to energize said blowing unit and to said recharging circuit for recharging said battery.

12. The drier set forth in claim 11 wherein said battery means is connected to the front portion of the drier and said blowing unit is connected to the base of the drier to thereby balance the weight of said blowing unit and battery means upon the head of the user.

13. The drier set forth in claim 12 wherein said sheaths are made of a fiberglass material.

14. A portable hair drier that allows the user to move about without restriction and which is insertable into an energizing unit apart from said drier, said drier comprising a hood shaped to conveniently rest upon the users head, an electrical heating element positioned within said hood in proximity of the hair to be dried, a projection extending from said drier that is insertable into said energizing unit, and circuit means within said hood connected to said element and having contacts on said projection, said unit including a compartment having an entrance therein and into which said projection is insertable, means connected to said compartment for opening and closing said entrance to prevent inadvertent access thereinto, an energizing circuit within said compartment adapted to be connected to a household electrical source that includes contacts that are connected to the contacts of said circuit means when the drier projection is inserted into said compartment through the entrance thereof to thereby energize said element, said contacts between said circuit means and said energizing circuit being disconnectable upon removal of the drier projection from said compartment so that the user can move about without restriction.

15. The energizing unit set forth in claim 14 wherein said compartment forms the bottom portion of a carrying case for the portable hair drier.

16. A portable hair drier that allows the user to move about without restriction, and an energizing and recharging unit apart from said drier and into which said drier is insertable, said drier comprising a hood shaped to conveniently rest upon the users head, a projection on said drier that is insertable into said energizing and recharging unit, an electrical heating element positoned within said hood in proximity of the hair to be dried, circuit means within said hood connected to said element and including contacts on said projection, an electrically operated blowing unit mounted at the base of said drier for circulating air within the hood in such a manner that said air is heated prior to passing through and over the hair to be dried, rechargeable battery means mounted at the front end of said drier including circuit means connected to said blowing unit, and recharging circuit for said battery including contacts mounted on said drier projection, and switch means for selectively connecting said battery to said circuit means to energize said blowing unit and to said recharging circuit for recharging said battery, said energizing and recharging unit comprising a compartment havng an entrance through which the drier projection is insertable, an energizing circuit within said compartment adapted to be connected to a household electrical source that includes contacts adapted to be connected to the contacts of the circuit means on said drier projection to energize the heating element within the hood for a predetermined time to obtain the desired temprature, a recharging circuit within said compartment adapted to be connected to the same household electrical source that includes contacts which are adapted to be connected to the contacts of the recharging battery circuit when the drier projection is inserted into said compartment, and wherein actuation of said energizing and recharging circuits within the unit is achieved by connecting said circuits to said electrical source and by insertng the projection on the drier into the compartment to contact the contacts thereon with the contacts of the energizing and recharging circuits.

References Cited UNITED STATES PATENTS 2,668,367 2/1954 Chedister 34-99 3,108,862 10/1963 Toulmin 3499 3,143,697 8/1964 Springer. 3,182,653 5/1965 Mavleos et a1. 126-204 FOREIGN PATENTS 895,213 11/1953 Germany.

FREDERICK L. MATTESON, JR., Primary Examiner. JAMES W. WESTHAVER, Examiner.

A. D. HERRMANN, Assistant Examiner. 

